Scrubber



June ll, 1935.

c. G. HAwLEY SCRUBBER Filed Feb. 2, 1932 3 Sheets-Sheet .2

- INVENTOR Char/es G//QW/ ATTORNEY S* June ll, 1935.

c. G. HAwLl-:Yl

SCRUBBER Filed Feb. 2, 1932 3 Sheets-Sheet I5 Patented June 11, 1935PATENT oFFicE SCRUBBER Charles Gilbert Hawley, Chicago, lll., assignorto Centrifix Corporation, Cleveland, Ohio, a corporation of OhioApplication February 2, 1932, Serial No. 590,491

5 Claims.

This application is related to my earlier applications applying to thesame arts and identified as Serial Number 463,734, filed June 23, 1930,and Serial Number 509,750, filed January 19, 1931.

This invention relates to improvements in centrifugal scrubbers anddriers, and involves a process of scrubbing gases, vapors and air in astate 0f flow. Such process comprises steps by which substances notwanted in a major volume of aeriform fluid are transferred to a minorbody of liquid, wherewith they may be removed or wasted. The processincludes and the novel apparatus provides for the intimate admixture ofthe lighter fluid with an appropriate liquid and immediate subsequentseparation from that liquid; to the end that the gas, vapor or air maybe discharged in a predetermined state of improvement or to the end thatthe liquid selected for use shall be charged with a desirable substanceor improved in character. By the means here provided varioud aeriformfluids may be cleaned or changed in nature or condition through theseparation of objectionable or of valuable substances or by the additionof absorbable substances. 0r if desired, heat may be transferred fromone fluid to the other. The purification of both natural andmanufactured gases and vapors, the dehydration thereof, and, theso-called conditioning of air and vapors exemplify one group of uses towhich this invention is suited. Recoveries of tars, oils, condensiblevapors and absorbable substances from natural and manufactured gasesexemplify another group.

Further, this invention has for its purpose, and comprises, an improvedprocess and apparatus wherein and whereby liquids of various kinds maybe, and are, changed in nature or condition through being heated orcooled, deprived of volatile burdens, or supplemented by the addition ofabsorbable substances; all by intimate admixture and contact with asupplied gas or gases appropriate to the individual needs. The aeration,the gassiication, the loading of liquids, and the cooling and heating ofliquids, all exemplify such uses of this invention.

Whatever the use or purpose. the invention proceeds by organizing astream of the aeriform fluid and causing that stream to rapidly descendtoward and vigorously impact a body of the liquid required for the givencase, thereby transferring heavier particles from the lighter to theheavier fluid-and continuously or progressively shattering anddispersing the liquid by means of and within the streams of lighterfluid, thus causing the intimate contact of the differing fluids'tocomplete the desired transfer of substances from one to the other.Following such controlled and dynamic contact, the lighter iiuid iscaused to rise slowly toward a point of egress. V It is caused to whirlas it rises and the lighter fluid ejects or separates any excess ofliquid which may have been entrained in the stage of intimate admixture.Obviously, the liquid remaining from the process is disposed of or istreated as its changed nature or condition may require, and likewise,the

aeriform fluid having been utilized or treated, passes-onward toward anydesired point of use or further treatment.

For sake of brevity hereinafter, the word gas will be used to define allgases, vapors, air and aeriform compounds. Specific names will besubstituted Whenever it is necessary to mention particular aeriformfluids.

The chief element of the novel apparatus embodying this inventioncomprises a closed container which is suited to the kind and pressure ofthe gas to be treated. The latter passes through the container andutilizing its own dynamic force, is first admixed with and thenseparated from a liquid suited to the purpose. In most instances thecontainer comprises an upright cylindrical drum and both the gas inletand gas outlet are provided at the top of the drum. The drum is keptpartly filled with the appropriate liquid, which liquid may be partly orwholly derived from the gas under treatment, though it is usuallysupplied from a separate source. The gas enters through a verticallypositioned pipe or nozzle which opens downward at a point above thesurface or level of the liquid. 'Ihe liquid therefore receives thedirect impact of the downflowing gas and in consequence most of theheavier substances carried by the gas and such as are4 absorbable by theliquid are forcibly driven into contact with the liquid and are retainedtherein. The process is attended by subsequently enforced contacts ofthe gas and liquid, brought about through the agency of awhirl-promoting tuyre combined with the lower end of the nozzle and bymeans of la definitely restricted mixing chamber which surrounds suchtuyre in the lower part of the drum and which chamber also constitutes amajor liquid separator; following which the gas is finally dried orseparated from liquid by a conjoined centrifugal separator provided inthe upper part of the drum.

The invention will be fully understood uponreference to the followingdetailed description and the accompanying drawings which depict theinvention in its best forms.

In said drawings, Fig. 1 is a vertical section of a scrubber and drierembodying the present invention, the section being taken upon the lineI-I of Figs. 2 and 3; Fig. 2 is a horizontal section on the irregularline 2-2 of Fig. l; Fig. 3 is a horizontal section on the line 3-3 ofFig. 1; Fig. 4 is a vertical sectional view, on the line 4-4 of Fig. 5,illustrating a modified form of the invention and, Fig. 5 is afragmentary horizontal section on the line 5-5 of Fig. 4.

The scrubbers embodying the present invention are constructed andintended for direct' inclusion in gas lines, and the energy required foreicient operation is derived directly from the moving gas. The scrubberhas no parts to which movement must be imparted. Instead, its presencein the gas passage causes collisions and movements which result` incleaning the gas by admixture with a liquid and in the drying of the gasbefore it leaves the scrubber. The few metal parts: making up thescrubber are all xed to resist :movement and it is completed andrendered most effective by a quantity or body of liquid, L, whichoccupies the lower part of the scrubber. That liquid receives the impactof the passing gas and is also violently admixed therewith, only to beinstantly separated therefrom and retained in the scrubber. The transferof substances takes place rapidly, various substances being retained bythe liquid, or if desired the gas is charged with substances taken fromthe liquid.

This scrubber is generally employed in treating gases and vapors atrelatively high .pressures and usually takes one or the other of theforms shown in Figs. 1 and 4. In'other words, Athe body of the scrubberusually comprises the strong cylindrical drum 2 having proper convexheads 3 and lII. It is supported in vertical position as by legs orcolumns 5. Figures 1 and 4 differ in some particulars which will beexplained, but in the main, are alike and for the sake of brevity, likeparts will be identified by the same reference marks.

A horizontal floor 6 about midway of the height of the drum divides thedrum into upper and lower compartments. The lower compartment containsthe before-mentioned liquid, L; also a gas inlet nozzle 1, and agas-and-liquid mixing and separating chamber 8. The upper compartment isdevoted to the collection and final drying of the gas before it leavesthe scrubber; and contains an individual centrifugal separator 9, andthe gas outlet I0. The gas enters the lower compartment through thedownward leading central nozzle 1, which terminates midway between thefloor 6 and the surface L of the body of liquid. A large central openingII in the floor 6 constitutes the gas outlet of the lower compartmentand through that opening I I, the outgoing gas enters the separator 9.The actual lower end of the nozzle 1 extends below the level L' beingformed by the tangentially bladed whirl-promoting tuyre T which ispartly submerged in the liquid. The bottom of that tuyre opens into thelower part of the liquid body L, as will be further explained.

The bottom of the mixing chamber 8 is formed by the surface of theliquid L; its top is formed by the oor 6. In the case of-Figs. 1 to 3,the outer wall of the mixing chamber 8 is formed by a cylindrical shellI2 which depends from the floor 6 and hangs well below the liquid levelL'. The cylindrical part I2 is of less diameter than the drum, leavingan annular space I3; and that space is employed as a drain for the uppercompartment in the drum, as will be further ex` plained. The floor 6 andthe wall I2 are tightly joined, as by welding, and both are fxedlysupported within the drum 2 by a number of fixed vertical spacers I3(see Figs. 2 and 3).v In the case of Figs. 4 and 5 the outer wall of themixing chamber 8 is provided by the wall 2 of the drum and the abovementioned drain I3 finds a counterpart in one or more vertical ducts I4,as shown in Figs. 4 and 5, which join openings I5 in the `floor 8 withthe underlying body of liquid L, serving as drains for the uppercompartment,

as will be further explained.

Each mixing chamber contains a circumferential liner I6, of lessdiameter and of less height than the mixing chamber, a circumferentialslot or opening I1 remaining between the upper edge of the liner and theunder side of the floor 6, and leading into the top of the annular spaceI8 surrounding the part I6. The latter may be better described as aseparating shell; for it takes part in the rst or major separation ofgas and liquid, following the forcible mixing thereof, as presently tobe described. In the case of Figs. l to 3, the liner I6 is supported bya plurality of vertical spacers I6'; whereas the liner I6 of Figs. 4 and5 is attached to the downspouts or drains I4 that hang from the openingsI5 in the floor. As Shown, the separating shells I6 extend well belowthe liquid level; and further, the space I8, back of or outside eachshell I6 is open at thebottom and hence in free communication with thelower part of the body of liquid L.

The partly submerged tuyre T comprises a circumferential series ofangularly disposed blades I9 which form a plurality of slot-liketangential tuyre openings 20, all having the same direction and leadinginto the space 8 within the separator shell I6. The upper ends of theblades are held in or by-a ring 2l that ts the lower end of thenozzle 1. The lower ends of the blades are held in or by a ring 22having within it an opening 23, preferably of the full internal diameterof the tuyre.

The tuyre T is a substantial and rigid element, and most conveniently,it is supported by a pair of cross-bars 24 that extend from side to sideof the separator shell I6 and which are detachably bolted thereto, aswell shown at points 25. Lugs 26 formed on the tuyre bottom or ring 22are bolted to respective cross-bars 24 and serve to hold the tuyre rmlyagainst rotation. The tuyre T may be fixed on the lower end of'thenozzle 1, such practice being followed in scrubbers of the smallersizes, but scrubbers of the larger sizes involve forces .which make itdesirable to both support and fasten the tuyre more firmly and topositively prevent its displacement by the surging liquid in which it issubmerged or by the torsional reaction of the gases leaving 'itsinclined or tangential tuyres 20.

An ample annular space 21 is provided between the top 2| of the tuyreand the iioor 6, beneath the opening I I; and through that opening thegas Whirls from the chamber` 8 and rises into the separator 9. As shownin Figs. l and 2, the opening II may be marked by an upstanding collarII'. The latter becomes a convenient part of the construction of theseparator 9, with the floor 6 serving to hold the circumferential seriesof blades or vanes 28 belonging thereto. But the blades 28 may be spacedaway from the opening I I and may rise directly from the floor, as shownin Figs. 4 and 5. The top of the separator is formed by the circularplate 29 which tightly surrounds the central nozzle 1. All parts (6, 28and 29) are preferably welded together and forma rigid and immovablestructure. The separator preferably includes and is completed by a lowcylindrical wall 30 which is concentric therewith and positioned betweenthe same and the inner wall of the drum 2. The wall 30 is spaced fromthe floor to provide a narrow opening or openings 3| for the dischargeof the liquid ejected by the separator, as hereinafter explained. The

part 30 rises somewhat above the separatortopA 29 and is surrounded by arelatively wide annular space 32, the bottom of which is formed by theoor 6.

As best shown in Figs. 2 and 5, the inclined blades 28 providerespective separators with many tangential outlets or tuyre openings 33,all having the same direction. The tuyre openings 33 are relativelynarrow and the height thereof being small, their aggregate area does notgreatly exceed the cross-sectional area of the inlet nozzle 1. Inconsequence, the gas is certain to emerge from the tuyre openings 33 athigh velocity and to meet the opposed wall 30 at acute angles, rel

sulting in an excellent centrifugal separation of all residues. The nearpresence of the surrounding wall 30 ensures a centrifugal separation ofhigh quality. i

The large openA space 34 above the separator constitutes the nalseparating and collecting chamber of the scrubber. The nozzle Iappearing in Figs. 1 to 3 extends downward through the drum top 3, andthe outlet I thereof is provided by a horizontal pipe IIJ which extendsfrom the central portion of the chamber 34 and opens outward through theside of the drum 2. In contrast,'the nozzle 'I of Figs. 4 and 5 issupplied with gas by way of a horizontal cross pipe 1a, both ends ofwhich preferablyv extend through the sides of the drum, one end thereofbeing closed as shown at 1b. The outlet I IJ of Fig. 4 may be placedeither -in the top 3 of the drum or may be like the pipe vI 8' andextend through the side of the drum, at right angles to the pipe 1a, asmay be most convenient. It is to be noticed that in both constructionsand by reason of the employment ofthe centrifugal separator the gas,rising from the lower compartment is delivered outwardly against theinner wall of the drum and must react from that point in order to reachthe outlet I0. High final eciency is thus ensured. y

The structure of Fig. 1 is preferred whenever it is convenient to havethe gas enter the drum through an axially positioned pipe. The crosspipe 'Ia of Fig. 4 is used where it is more convenient to have the gasenter the drum at the side. The construction including the pipe la is offurther advantage because the closed end of the pipe 1a provides a gasand dust cushion or pocket 1c, a Ydetail which prevents excessive wear.

Liquid is supplied to the drum through a feed pipe 35 containing asuitable valve 36 (see Fig. l). For draining sludge and liquid from thedrum, a blow-01T pipe 31 is provided at the bottom of the drum. Theblow-off valve 38 appears in Fig. 1. By manipulating the valves 36 and38 or equivalent means, the-devel L of 'the absorbing liquid ismaintained substantially as indicated in Figs. 1 and 4.

l When charged with liquid, L, of a kind suited to the gas to betreated, the scrubber is ready for operation; and, gas being admittedthrough the nozzle 'I and released through the outlet I0, the operationproceeds as follows: 1

The stream of gas organized by. the nozzle directly. impacts -theopposed liquid within the tuyre T; tending to depress the exposedsurface,

as shown in the drawings. AThe heavier substances carried by the gas arethus directly delivered to the liquid and are retained thereby, the gaspassing off laterally through the many tangential openings 20 of thetuyre T. As will be apparent from the use ofsuch tuyres, the gas takeson a violent swirling or vortexial movement within the chamber 8 and asa result the liquid therein is violently agitated and admixed with thegas. In addition, a direct centrifugal separation is caused to takeplace upon the separating shell or wall I6 and thus further purificationof the gas is brought about.V -The central opening II provides the onlyoutlet through which the gas may escape from the chamber 8 and havingimparted and swept the liquid, the gas whirls upward within the chamber8. Much of the liquid vis projected against the wall I6 and iswhirlingly carried to the top thereof, where it is centrifugallydischarged into the surrounding space I8. Falling therein the-rejectedliquid rejoins the liquid body L in thelower part of the drum. Thus thebefore-mentioned major separating effect is accomplished. Thereupon thegas reacts toward the axis of the drum and whirls inward and upwardthrough the passage 2'I, thus entering the separator 9. By means of thelatter, the gas stream is subdivided into many tangential streams which,as explained, emerge at high velocity and 'after impacting the opposedwall 30, whirl upward within the annular space between the tuyre blades28 and the wall 3U.

A ne centrifugal separation is produced by the action next abovedescribed, and the residual liquid collected upon the wall 30 iscentrifugally discharged therefrom, Aboth through the slot 3| and acrossthe upper edge or rim of the wall 30. Obviously, there is littlemovement of the gas in the space 32 and little remaining tendency toelevatel moisture into the. upper part of the drum. The residualmoisture which is sepa rated in the upper chamber of the drum` drainsdownward, off the floor 6 and rejoins the liquid body L, through thespace I3 of Fig. l and through the ducts I4 of Figs. 4 and 5.

Attention is called to the fact that the liquid level L" in the outerdrain passage or passages is slightly higher than'the level L within thebody of the scrubber. This greater height of the liquid column whichbelongs to the upper part of the drum is explained by the fact that thegas pressure Within the chamber 8 is necessarily higher than thepressurewithin the collection chamber 34; and the difference of pressure isreflected by the comparative levels L and L. It is the practice toprovide these scrubbers with liquid level indicators, usually gaugeglasses, in order that the level L may be known and maintained. Thatlevel being of the greater importance, the gauge should be connectedwith the space 8 rather than with either of the outer drain passageshere shown.

Upon 'emerging from the collar or wall 36 of the separator 9, thegaswhirls outward and upward within the chamber 34 and its velocity ismuch reduced by expansion. Thus a nal elimination and precipitation ofmoisture is ensured. Reacting then toward the 'axis of the drum thepurified gasnally departs through the outlet I8; which as stated, ispositioned to take the gas from the central portion of the drum.

'Ihe foregoing may be taken as descriptive of the process of purifyingvarious aeriform fluids and resulting in the abstraction or separationof retention thereof by the liquid employed. The mere operation of theprocess is not changed when the purpose is to charge or burden a givengas with moisture or vapors taken from an appropriate liquid L withinthe scrubber. In such cases, the violent impacts and the centrifugalmixing of the liquid and gases result in the quick transfer of desiredsubstances, from the liquid to the gas; and the subsequent operation ofthe separator 9 has the effect of preventing the physical entrainment ofliquid in the outgoing gas.

The scrubber has an obvious use in the transfer of heat from one to theother of the mediums employed.

The many advantages possessed by the scrubber will be apparent to thoseskilled in the art. 'I'his scrubber is peculiar in that it works bestwith gas moving at high velocity. Its operation is not materiallyaffected by ordinary variations of pressure or velocity. The scrubber isselfcleaning and not apt to become clogged. It operates with a minimumdrop of pressure, between inlet and outlet. It is of high eiiciency,occupies comparatively little space, and is of comparatively low cost.

Having thus described my invention I claim as new and desire to secureby Letters-Patent:-

1. The herein described scrubber comprising, in combination, a closedchamber containing a horizontal floor that divides it into upper andlower compartments, a gas inlet nozzle leading downward through saidfloor and terminating in an open bottomed whirl-promoting tuyresupported within said lower compartment, a separating wall surroundingsaid tuyre and spaced from said floor, said wall depending toward thebottom of said lower compartment, a drain passage leading from the topof said floor toward the bottom of said lower compartment, another'drain passage leading toward the bottom from the top of said wall, aco-axial gas passage. provided in said iloor, a tangentially bladedcentrifugal separator forming a restricted gas outlet leading from saidpassage into said upper compartment, and, a gas outlet leading centrallyfrom said upper compartment.

2. The herein described scrubber, vcomprising a vertical drum having agas outlet in its top, in combination with a floor containing a centralgas passage and dividing the drum into upper andlower compartments, adrain belonging to the upper compartment and leading downward from theperipheral portion of said floor, a gas inlet nozzle extending downwardthrough said passage and of ,less diameter, a bottomless whirlpromotin'gtuyre forming the terminus of said nozzle within said lower compartment,a cylindrical separating Awall therein surrounding said tuyre and ofgreater diameter than said passage, the upper edge of said wall beingspaced from the under side of said oor, a circumferen tial drain outwardof said wall and leading downward from the under side of said floor,means adapted to maintain a stand of liquid within f said drum andpartly submerging said tuyre,

separating wall and drains, a tangentially bladed tuyre erected on thetop of said oor in compassage and of less diameter, a bottomlesswhirlpromoting tuyre forming the terminus of said nozzle within saidlower compartment, a cylindrical separating wall therein surroundingsaid tuyre and of greater diameter than said passage, the upper edge ofsaid wall being spaced from the under side of said floor, acircumferential drain outward of said wall and leadingl downward fromthe under side of said floor, and means adapted to maintain a stand ofliquid Within said drum and partly submerging` said tuyre, separatingwall and drains.

4. The herein described scrubber, comprising a vertical drum having agas outlet in its top, in combination with a floor containing a centralgas passage and dividing the drum into upper and lower compartments, adrain belonging to said upper compartment and leading downward from theperipheral portion of said floor, a gas inlet nozzle extending downwardthrough said passage and of less diameter, means adapted to maintain astand of liquid within said lower compartment and partly submerging saiddrain, a tangentially bladed tuyre erected on the top of said floor incommunication with said passage, and, a cylindrical separating wallerected on said floor spaced between said bladed tuyre and the innerwall of the drum, substantially as and for the purposes described.

5. The herein described process of treating dust-laden gas that consistsin directing a stream thereof downward and perpendicularly against thesurface of a body of appropriate liquid thereland liquid in the regionsurrounding the place of such -impact and thus mixing, the partiallypurified gas with liquid and accomplishing the transference of furtherdust to said liq'uid, immediately permitting such whirling movement tocentrifugally separate the major part of the dust laden liquid from thewhirling gas, returning the separated liquid to said body and allowingthe immediate upward escape of the whirling gas with the same continuingupward movement into and beyond an upper zone but restricting suchupward outflow to swift whirling movement within said upper zone therebyseparating residual liquid, returning such residue to said body whilepermitting the whirling and upward expansion of the escaping gas andnally releasing the gas beyond said zone.

CHAS. GILBERT HAWLEY.

